Common words, and even specialized words in philosophy, can have several meanings. Assuming different meanings of words often leads to serious miss-communications. The following definitions are chosen for their expected utility in explaining the science of understanding morality as an evolutionary adaptation. The science strongly suggests the choice of definitions for particular words (and concepts) such as altruism, self-interest, and enforced moral standard. Attempting to use definitions that are inconsistent with the science may make arguments so convoluted and complex as to be almost  impossible to follow.

As seemed appropriate, I included some notes on why the definition being used is preferable to common alternatives.

These definitions are included because they are important for understanding morality as an evolutionary adaptation. Words that are not specifically defined here should be assumed to have their standard meanings in the context of evolutionary science, game theory, and moral philosophy.

Glossary words and phrases:

Altruistic act
Enforced cultural norm (enforced moral standard)
Evolution
Functional morality
Moral fact (Descriptive moral facts, Objective moral facts, Imperative moral facts)
Oughts (Imperative Oughts, Instrumental Oughts, Emotional Oughts)
Pro-social acts
Self-interest
Social morality  (enforced social morality)

Altruistic act – Acting without consideration of future net benefits, at a cost to one’s self, and benefiting other people.
– My Blog Post  “Is it more useful to define altruism to be contingent on ‘no consideration of expectations’ rather than ‘expectations’ as is common?” argues that altruism must be defined similarly to the above definition in order to enable the existence of instrumental rational justifications for acting altruistically. Unfortunately, common definitions of altruism used in ethical discussions make  instrumental rational justifications for acting altruistically a logical impossibility. For example, as soon as you expect instrumental compensation or benefits for accepting the burdens of altruism, the definition says you cannot be acting altruistically.
– Also, using “without consideration” phrasing (rather than making altruism about the expectations of the actor as is often done) broadens this definition to be meaningful for all beings including bacteria, who have no intent. Bacteria provide many examples of acting at a cost to themselves in ways that benefit others. See  David Sloan Wilson’s description of some charming examples of bacterial altruism in his book Evolution for Everyone: How Darwin’s Theory Can Change the Way We Think About Our Lives. Defining this behavior by bacteria as ‘not-altruistic’ would be forcing a division where science does not and, by doing so, greatly muddying the waters.

Enforced cultural norm (enforced moral standard) – An enforced cultural norm is one whose violation commonly engenders the emotion indignation within that culture and the idea that the violator deserves punishment, even though the violator may not actually be punished.
– Consider the norm, “Slavery is morally acceptable”. It appears to be empirically true that no culture has ever thought that NOT keeping slaves, by itself, deserves punishment. So “Slavery is morally acceptable” is a norm, but not an enforced norm. Enforced cultural norms relevant to slavery might include slave’s obligation to serve their masters and the obligation of all free men to unselfishly help put down slave revolts and refrain from claiming slavery is immoral.
– It also appears to be empirically true that all past and present enforced moral standards advocate behaviors that are altruistic. For example, “Do not steal, lie in court, or kill” advocates altruism in that people ought to not “steal, lie in court, or kill”, which when they really want to “steal, lie in court, or kill” and believe doing so would be beneficial, would be a cost to themselves, but a benefit to society. Enforced cultural norms for circumcision and prohibiting eating shrimp can be costly to the individual but beneficial for the group as markers of membership and commitment to a more cooperative sub-group that excludes others.

Evolution – A substrate neutral process of variation, selection, and reproduction.
The two substrates relevant to morality are biology and culture. For biological evolution, selection is by whatever increases inclusive reproductive fitness and reproduction is normal biological reproduction.  For culture, selection is by whatever people find attractive about a norm; reproduction of norms is largely by copying.
– Assuming that evolution means only biological evolution makes understanding morality as an evolutionary adaptation almost impossible. Morality is a product of both biological and cultural evolution.

Functional Morality – A definition of what is moral based on the primary reason that enforced moral standards (enforced cultural norms) exist in cultures.
– See Phillip Kitcher’s 2011 book “The Ethics Project” for a defense by a well-respected philosopher. Kitcher proposes the function of morality to be, at least originally, something like “overcoming altruism failures that reduce well-being”.
– Kitcher and I differ in that I argue for a different function of morality in cultures and I hold that function has been constant. I see “the primary reason that enforced cultural norms exist in cultures” as a truth apt empirically determinable fact, in the provisional sense of truth that is normal in science. That is, what the function of enforced cultural norms in groups is should be determined by meeting relevant criteria from science about facts. Relevant to the function of morality, such criteria could include 1) no contradiction with known facts, 2) explanatory power for myriad descriptive facts and puzzles about morality, and 3) unity with the rest of science. I argue that the function “to increase the benefits of cooperation in groups by advocating altruistic acts” meets these criteria better than any other available option and, indeed, no other option is even remotely close.
– As a truth apt claim, no functional morality definition entails any imperative oughts that are binding regardless of needs and preferences. Like other facts from science, it can only be the basis of an instrumental ought whose binding power is judged based on its ability to satisfy an overriding desire, perhaps durable happiness over a lifetime.

Moral fact – There are three kinds of moral facts relevant to understanding social morality as an evolutionary adaptation.

• Descriptive moral facts are facts such as “In culture X, the moral standard Y is enforced” and “Human moral concept or intuition X is puzzling in that it contradicts moral concept or intuition Y”.

– The reality of descriptive moral facts is not controversial.

• Objective moral facts are facts about morality that would still be true independent of the existence of people, but are not necessarily somehow binding regardless of people’s needs and preferences. Objective moral facts are descriptive facts that would still be true independent of the existence of people.

– The reality of objective facts is controversial. I argue that there is at least one moral fact based on what the function of morality is. That moral fact is “The function of social morality is to increase the benefits of cooperation in groups by altruistic acts”. This fact is as objectively true, and species and even biology independent, as the mathematics of game theory it is based on.

•  Imperative moral facts are facts about what people ought to do that are supposed to be somehow binding regardless of people’s needs and preferences.

– Imperative moral facts appear to be what Michael Ruse is talking about when he perversely, and misleadingly, declares “Morality is an illusion!” So far as I know, it is true that any appearance of the reality of imperative moral facts is an illusion, and is the illusion behind ‘magic’ oughts.. However, Ruse’s claim is perverse and misleading in that just because there are no imperative moral facts does not mean there are no objective moral facts, or at least one objective moral fact, with the normal sense of the word “fact”.

Oughts – There are three kinds of oughts relevant to morality

• Imperative ought – An ought that is put forward as somehow universally binding regardless of people’s needs and preferences.

– No means has ever become generally accepted by which reality makes such oughts binding. Till some means by which reality makes such oughts universally binding has become generally accepted, I will feel free to refer to Imperative oughts as ‘magic’ oughts.
– Enforced cultural norms (moral standards) may be commonly presented as universally binding. But it is empirically true that when following them would be against the needs and preferences of the group as a whole, such norms suddenly become less binding. Mindlessly following them can even be viewed as deserving punishment (being immoral). For example, mindlessly following “Do unto others as you would have them do unto you” when dealing with criminals and in times of war.

•  Instrumental ought – An ought whose burdens are rationally justified based on facts and overriding needs and preferences.

– For example, it might be argued that “Based on knowledge from game theory and psychology, people ought (instrumental ought) to accept the burdens of Altruistic Cooperation morality if they desire to increase their experience of durable well-being (happiness) over their lifetime”.

• Emotional ought – An ought motivated by emotions triggered by our moral intuitions.

– These can be quite powerful and motivate people to act directly contrary to even  their overriding needs and preferences, such as those for durable well-being over a lifetime.
– Emotional oughts are biological adaptations that increased the reproductive fitness of our ancestors even though they sometimes motivated behaviors, such as bravery and loyalty, which decreased individual reproductive fitness.
– Human moral intuitions are critically based on another biological adaptation. Over time, our moral intuitions can automatically transform whatever cultural enforced norms (nominal imperative oughts) we accept the burdens of into emotional oughts that can be immune to reason or considerations of personal well-being. So far as I know, this biological adaptation does not have a name, except perhaps conscience, but that does not seem to me to capture its power.

Pro-social acts – All acts that benefit others are pro-social.
– Altruistic acts differ in that a cost to the actor is required. For example, someone who is self-interestedly motivated to participate in a money economy may greatly benefit society (is acting pro-socially), but as was famously pointed out by Adam Smith long ago, is not acting altruistically.
– It would be roughly consistent with the goals of Utilitarianism to assert that all pro-social acts are moral and morality does not have any necessary altruistic component. However, this approach causes logical problems in answering the question “What norms ought to enforced in groups (be moral standards)?” For example, should people deserve punishment merely for NOT self-interestedly participating in a money economy? That would be silly. Sensible enforced cultural norms regarding not self-interestedly participating in a money economy might include “Fulfill your obligations to other people in your groups, such as your family” and “Don’t ‘sponge’ off of other people and take advantage of their altruism”.

Self-interest – Acting in one’s self interest is to act in sustainable ways that are likely to enable meeting a desire such as increased durable well-being over a lifetime.
– Acting in one’s self-interest may not increase other people’s well-being and will often require acting against one’s immediate needs and preferences. However, in part due to our biology, acting in one’s self interest may often require acting at a cost to one’s self in order to benefit others, with no consideration of future net benefit to your-self. Acting in one’s self-interest, by this definition, may require acting altruistically.

Social morality – Social morality is the subcategory of ethics dealing with interactions with other people. More self-interested moral norms that form important parts of answers to the broad questions “How should I live?” and “What is good?” are outside the sub-category of social morality.

• .Enforced social morality – Morality defined by enforced cultural norms whose violation commonly engenders the emotion indignation and the idea that the violator deserves punishment (though the violator may not actually be punished). Moral disputes between most non-philosophers concern which social morality ought to be enforced in their society.  Enforced social norms (enforced moral standards) advocate behaviors that is in some sense altruistic. Unenforced social norms state what is permissible, for example slavery which is not altruistic, rather than a possible enforced cultural norm, for example unselfishly aiding in putting down slave revolts which is altruistic.